The present invention relates to a method and a controller for controlling a power train of a vehicle having a number of modes of operation.
Different functions of a power train of a vehicle are represented by separate software modules. For instance, in a modern vehicle there are software modules for controlling an engine speed of a combustion engine, a module for controlling an active damping of the power train, a module for controlling start and stop of the combustion engine, and a module for controlling a clutch of the power train. Combination of these software modules leads to a functional risk which has to be safeguarded, since the software modules have complex and sometimes unknown interactions with one another. A disadvantage of the interaction of the different software modules is the deceleration of the process of developing the power train since modifications on one software module might influence the function of another software module. Furthermore, with the increasing complexity of the software modules of a power train and the increasing number of the modules, insight into the overall system decreases. As a result, misbehavior of the whole system cannot be reduced to a specific part of the system.
Furthermore, since there is no communication between the different software modules of the power train (sometimes referred to as a system), some of these modules may need redundant information for providing the same functionality. Because of the presence of many non-linear characteristic curves, an analysis of stability of the whole power train is difficult to achieve. Although it is possible to linearize parts of the whole system, this is extensive work and for the verification of stability not necessarily sufficient.
It is therefore an object of the present invention to provide a method and a controller for controlling a power train of a vehicle to obviate and mitigate the afore-mentioned disadvantages.
According to the invention, a method for controlling a power train of a vehicle having a number of modes of operation is provided. The method comprises the steps of providing a first controller for controlling of a first function of the vehicle; providing at least one second controller for controlling of a second function of the vehicle; combining the first controller and the at least one second controller in a joint controller having a state observer and a number of controlling entities, the joint controller being operated by a set of formal controlling parameters assigned to the controlling entities; and switching actual parameters of the set of formal controlling parameters according to a current mode of the number of modes of operation.
In accordance with another aspect of the invention, a controller for controlling a power train of the vehicle having a number of modes of operation is provided. The controller comprises a first controller for controlling a first function of the vehicle; at least one second controller for controlling of a second function of the vehicle; and a joint controller combining the first controller and the at least one second controller, the joint controller having a state observer and a number of controlling entities and being operated by a set of formal controlling parameters assigned to the controlling entities. The joint controller is adapted to switch actual parameters of the set of formal controlling parameters according to the current mode of the number of modes of operation.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the function of the related elements of the structure and the combination of parts, will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form part of this specification.